code: def test_convert_pair_atom_to_voxel(self):
      N = 5
      M = 6
      coordinates1 = np.random.rand(N, 3)
      coordinates2 = np.random.rand(M, 3)
      atom_index_pair = (2, 3)
      box_width = 16
      voxel_width = 1
      indices = voxel_utils.convert_atom_pair_to_voxel(
          [coordinates1, coordinates2],
          atom_index_pair,
          box_width,
          voxel_width,
      )
      assert indices.shape == (2, 3)
  
file_path: deepchem/deepchem/utils/test/test_voxel_utils.py
imports: import numpy
  import unittest
  from deepchem.utils import voxel_utils
  from deepchem.utils import hash_utils
label_desc: Use image node_id 2 for calling the TestVoxelUtils obj's underlying member method code with example usage: obj.test_convert_pair_atom_to_voxel() without return types